The overall purpose of this training grant is to provide postdoctoral training to young basic scientists and physicians in the area of neurobiology of substance abuse, with a focus on the mode of action of psychostimulant and opiate drugs at the genetic, molecular, circuit and behavioral levels. Our objective is to provide an exciting and innovative environment with world class facilities and faculty to develop the next generation of scientists working in drug abuse. Training will take place in the multidisciplinary setting at the University of Michigan. The 15 faculty are all NIDA grantees (or Co-Investigators) and have expertise in the neurobiology of substance abuse, with particular emphasis on the area of opioid and psychostimulant drugs. The focus of the proposal is the training of Ph.D. and M.D. postdoctoral fellows in state-of-the-art approaches for studying mechanisms underlying abuse of psychoactive drugs. This includes studying the genetic, developmental and environmental factors that lead to vulnerability to substance abuse: the mode of action of drugs of abuse at the molecular, cellular, anatomical and behavioral levels;and the long-term consequences of psychoactive drugs on the brain, as mediated through mechanisms of neural plasticity. The working assumption is that the functional and structural brain remodeling associated with chronic drug use lies at the basis of tolerance, sensitization, physical dependence, and psychological addiction to these drugs. The drug abuse research community at the University of Michigan is of high quality and has a long history in the field. Beyond their individual strengths, the training faculty members have long-term scientific and training relationships with each other. These historical strengths have recently been significantly enhanced with a number of initiatives at the University of Michigan, designed to facilitate life science research in general, and neuroscience research in particular. They include state-of-the-art tools for mouse and rat genetics, genomics, proteomics, and informatics. Thus, our trainees will profit from a highly sophisticated, yet supportive, research and training environment.